<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>test</title>
<script>

alert(typeof 1);				// 返回字符串"number"
alert(typeof "1");				// 返回字符串"string"
alert(typeof true); 			// 返回字符串"boolean"
alert(typeof {});				// 返回字符串"object"
alert(typeof []);				// 返回字符串"object "
alert(typeof function(){});	// 返回字符串"function"
alert(typeof null); 			// 返回字符串"object"
alert(typeof undefined); 		// 返回字符串"undefined"


</script>
</head>
<body>
</body>
</html> 
